Read by QxMD icon Read

Forward osmosis

S Liyanaarachchi, S Muthukumaran, Joshua Kaiser, Paul Rogers, Li Shu, Ho Kyong Shon, V Jegatheesan
Diffusion coefficient of solutes through a porous membrane media is different from diffusion coefficient through a free homogenous media. Porosity, tortuosity and the thickness of the membrane significantly affect the diffusion through a specific thickness of a membrane and therefore it is termed as effective diffusion coefficient (Deff ) which is lower than the actual diffusion coefficient, D. The Deff of single or dual solutes through a porous membrane layer are well documented but not for multiple salts...
March 8, 2018: Journal of Environmental Management
Wei Cheng, Xinglin Lu, Yi Yang, Jin Jiang, Jun Ma
Thin film composite (TFC) membranes are the gold standard for the application of forward osmosis (FO) in seawater desalination and wastewater treatment. However, bidirectional mass transport phenomena in this process still hinder its wider application. A deeper understanding of ion transport behavior in various solution conditions is critical for the fabrication of FO membrane and future development of FO process. In this work, we systematically investigated the influences of solution chemistry on ion mass transport in TFC FO membranes...
March 2, 2018: Water Research
P Kuntke, T H J A Sleutels, M Rodríguez Arredondo, S Georg, S G Barbosa, A Ter Heijne, Hubertus V M Hamelers, C J N Buisman
In recent years, (bio)electrochemical systems (B)ES have emerged as an energy efficient alternative for the recovery of TAN (total ammonia nitrogen, including ammonia and ammonium) from wastewater. In these systems, TAN is removed or concentrated from the wastewater under the influence of an electrical current and transported to the cathode. Subsequently, it can be removed or recovered through stripping, chemisorption, or forward osmosis. A crucial parameter that determines the energy required to recover TAN is the load ratio: the ratio between TAN loading and applied current...
March 9, 2018: Applied Microbiology and Biotechnology
Qiaozhen Chen, Wenxuan Xu, Qingchun Ge
Suitable draw solutes are crucial to maximize the potential of forward osmosis (FO) in water treatment. In this study, a novel three-dimensional, multi-charge draw solute of oxalic acid (OA) chromium complex in tetramethylammonium salt of [N(CH3)4]3[Cr(C2O4)3] (NMe4-Cr-OA) was developed for electroplating wastewater treatment using FO processes. The newly designed NMe4-Cr-OA has a Cr-centred octahedral structure and can ionize a multi-charge anionic [Cr(C2O4)3]3- and three cationic [N(CH3)4]- in its aqueous solution...
March 8, 2018: Environmental Science & Technology
Xiaoye Song, Ming Xie, Yun Li, Guoxue Li, Wenhai Luo
Osmotic membrane bioreactor (OMBR), which integrates forward osmosis (FO) with biological treatment, has been developed to advance wastewater treatment and reuse. OMBR is superior to conventional MBR, particularly in terms of higher effluent quality, lower membrane fouling propensity, and higher membrane fouling reversibility. Nevertheless, advancement and future deployment of OMBR are hindered by salinity build-up in the bioreactor (e.g., up to 50 mS/cm indicated by the mixed liquor conductivity), due to high salt rejection of the FO membrane and reverse diffusion of the draw solution...
February 23, 2018: Bioresource Technology
Qingchun Ge, Cher Hon Lau, Minghua Liu
The potential of forward osmosis for water treatment can only be maximized with suitable draw solutes. Here a three-dimensional, multi-charge draw solute of decasodium phytate (Na10-phytate) is designed and synthesized for removing organic arsenicals from water using a hybrid forward osmosis (FO) - membrane distillation (MD) process. Efficient water recovery is achieved using Na10-phytate as a draw solute with a water flux of 20.0 LMH and negligible reverse solute diffusion when 1000 ppm organic arsenicals as the feed and operated under ambient conditions with FO mode...
February 28, 2018: Environmental Science & Technology
Seungho Kook, Chivukula D Swetha, Jangho Lee, Chulmin Lee, Tony Fane, In S Kim
Forward osmosis (FO) membranes fall into the category of nonporous membranes, based on the assumption that water and solute transport occur solely based on diffusion. The solution-diffusion (S-D) model has been widely used in predicting their performances in the coexistence of hydraulic and osmotic driving forces, a model that postulates the hydraulic and osmotic driving forces have identical nature. It was suggested, however, such membranes may have pores and mass transport could occur both by convection (i...
March 1, 2018: Environmental Science & Technology
Syeed Md Iskander, John T Novak, Zhen He
In this work, a microbial desalination cell (MDC) was employed to desalinate the FO treated leachate for reduction of both salinity and chemical oxygen demand (COD). The FO recovered 51.5% water from a raw leachate and the recovery increased to 83.5% from the concentrated leachate after desalination in the MDC fed with either acetate or another leachate as an electron source and at a different hydraulic retention time (HRT). Easily-degraded substrate like acetate and a long HRT resulted in a low conductivity desalinated effluent...
January 31, 2018: Bioresource Technology
Masoud Rastgar, Ali Bozorg, Alireza Shakeri
To lower the unfavorable internal concentration polarization effect in forward osmosis (FO) membranes, support layers of highly porous interconnected structures with specifically large surface-to-volume ratios are indispensable. Herein, zinc oxide (ZnO) has been introduced as a new template to manipulate the porous structure of polyethersulfone (PES) support layer. The ZnO can be readily synthesized as desired in different dimensionally controlled nanostructures. The performance of the FO membrane was initially ameliorated in terms of permeability and selectivity through simple incorporation of ZnO nanostructures in the PES support layer...
February 6, 2018: Environmental Science & Technology
Saikat Sinha Ray, Shiao Shing Chen, Nguyen Cong Nguyen, Hau Thi Nguyen, Nguyen Phuoc Dan, Bui Xuan Thanh, Le Thuy Trang
Selection of a proper osmotic agent is important to make the forward osmosis (FO) feasible. The objective of this study was to enhance FO by lowering reverse solute flux and maintaining high water flux. Poly(propylene glycol) with molecular weight of 725 Da (PPG-725) was found to possess high osmolality, making it a strong candidate for using as a draw agent. In addition, to reduce the partial leakage of draw solute, a non-ionic surfactant (Triton X-114) has been incorporated. Typically, when the hydrophobic tails of Triton X-114 interacted with the membrane surface, a layer on the surface of membrane is produced to constrict the pores and thus minimize the reverse solute flux...
January 4, 2018: Journal of Environmental Management
Ming Xie, Wenhai Luo, Hao Guo, Long D Nghiem, Chuyang Y Tang, Stephen R Gray
We investigated transport mechanisms of trace organic contaminants (TrOCs) through aquaporin thin-film composite forward osmosis (FO) membrane, and membrane stability under extreme conditions with respect to TrOC rejections. Morphology and surface chemistry of the aquaporin membrane were characterised to identify the incorporation of aquaporin vesicles into membrane active layer. Pore hindrance model was used to estimate aquaporin membrane pore size as well as to describe TrOC transport. TrOC transport mechanisms were revealed by varying concentration and type of draw solutions...
December 28, 2017: Water Research
Detao Qin, Zhaoyang Liu, Zhi Liu, Hongwei Bai, Darren Delai Sun
Wastewaters with high concentrations of organic pollutants pose a great challenge for membrane filtration due to their severe fouling propensity. In this study, a hydrogel forward osmosis (FO) membrane is explored for treating wastewaters of high concentration organic pollutants. This FO membrane has an ultrathin hydrogel selective layer, which is highly hydrophilic (water contact angle: as low as 18°) and smooth (surface roughness: <5 nm). Investigated with typical organic foulants (protein, alginate, humic acid, and oil) of high concentration (2000 ~ 20000 mg/L), this hydrogel FO membrane exhibits remarkably superior antifouling capability, with its water flux decline ratio lower than a quarter of commercial FO membrane's under identical experimental conditions...
January 3, 2018: Environmental Science & Technology
Yuntao Zhao, Xiao Wang, Yiwei Ren, Desheng Pei
In this work, mesh-embedded polysulfone (PSU)/sulfonated polysulfone (sPSU) supported thin film composite (TFC) membranes were developed for forward osmosis (FO). The robust mesh integrated in PSU/sPSU sublayer imparts impressive mechanical durability. The blending of hydrophilic sPSU in PSU sublayer affects the hydrophilicity, porosity, pore structure and pore size of mesh-embedded PSU/sPSU substrates, and the total thickness, crosslinking degree and roughness of the corresponding TFC-FO membrane active layers...
December 26, 2017: ACS Applied Materials & Interfaces
N Singh, I Petrinic, C Hélix-Nielsen, S Basu, M Balakrishnan
Treatment of sugarcane molasses distillery wastewater is challenging due to the presence of complex phenolic compounds (melanoidins and polyphenols) having antioxidant properties. Due to zero liquid discharge regulations, Indian distilleries continue to explore effective treatment options. This work examines the concentration of distillery wastewater by forward osmosis (FO) using aquaporin biomimetic membranes and magnesium chloride hexahydrate (MgCl2.6H2O) as draw solution. The operational parameters viz. feed solution and draw solution flow rate and draw solution concentration were optimized using 10% v/v melanoidins model feed solution...
December 8, 2017: Water Research
Hongtao Cui, Hanmin Zhang, Wei Jiang, Fenglin Yang
Reverse draw solute diffusion not only reduces the water flux in forward osmosis (FO), but also contaminates the feed solution and eventually increases the regeneration cost of draw solution. In the present study, a new polyelectrolyte was synthesized as FO draw solute to address this problem. Acrylic acid and sodium p-styrenesulfonate monomers with hydrophilic group were used to fabricate carboxylate polyelectrolyte through free radical polymerization reaction. Results demonstrated that the osmotic pressure of carboxylate polyelectrolyte solution had a good linear relationship with concentration, and the viscosity of 0...
February 2018: Environmental Science and Pollution Research International
Wanzhu Zhang, Lin Wang, Bingzhi Dong
The fouling behavior during forward osmosis (FO) was investigated. Tannic acid was used as a model organic foulant for natural organic matter analysis since the main characteristics are similar, and calcium ions were added at different concentrations to explore the anti-pollution capability of FO membranes. The initial permeate flux and calcium ions strength were varied in different operating conditions to describe membrane fouling with membrane cleaning methods. The observed flux decline in FO changed dramatically with the type of foulant and the type of draw solution used to provide the osmotic driving force...
December 2017: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Sung-Ju Im, Jungwon Choi, Jung-Gil Lee, Sanghyun Jeong, Am Jang
A new concept of volume-retarded osmosis and low-pressure membrane (VRO-LPM) hybrid process was developed and evaluated for the first time in this study. Commercially available forward osmosis (FO) and ultrafiltration (UF) membranes were employed in a VRO-LPM hybrid process to overcome energy limitations of draw solution (DS) regeneration and production of permeate in the FO process. To evaluate its feasibility as a water reclamation process, and to optimize the operational conditions, cross-flow FO and dead-end mode UF processes were individually evaluated...
March 2018: Chemosphere
Yongjun Choi, Tae-Mun Hwang, Sanghyun Jeong, Sangho Lee
Unlike reverse osmosis (RO) that is dominated by the hydraulic pressure differential, forward osmosis (FO) uses the osmotic pressure gradient as the driving force between a dilute feed solution and a concentrated draw solution across a membrane. High pressure is not required in FO, which means that FO can be used as an alternative to RO as an energy-saving separation process in desalination technology. However, a major limiting factor of the FO process is the internal concentration polarization (ICP). Because of the stagnant environment inside the porous supporting layer of a FO membrane, it is difficult to mitigate the ICP by simply increasing the shear stress or promoting turbulence...
March 2018: Ultrasonics Sonochemistry
Madhavi Dahanayaka, Bo Liu, Zhongqiao Hu, Qing-Xiang Pei, Zhong Chen, Adrian Wing-Keung Law, Kun Zhou
Stacked graphene (GE) membranes with cascading nanoslits can be synthesized economically compared to monolayer nanoporous GE membranes, and have potential for molecular separation. This study focuses on investigating the seawater desalination performance of these stacked GE layers as forward osmosis (FO) membranes by using molecular dynamics simulations. The FO performance is evaluated in terms of water flux and salt rejection and is explained by analysing the water density distribution and radial distribution function...
November 22, 2017: Physical Chemistry Chemical Physics: PCCP
Sung-Ju Im, Jungwon Choi, Sanghyun Jeong, Am Jang
We tested the possibility of energy-saving water treatment methods by using a pump-less forward osmosis (FO) and low-pressure membrane (LPM) hybrid process (FO-LPM). In this pump-less FO-LPM, permeate migrates from the feed solution (FS) to the draw solution (DS) through the FO membrane by use of osmotic pressure differences. At the same time, within the closed DS tank, inner pressure increases as the DS volume increases. By using the DS tank's internal pressure, the LPM process works to re-concentrate the diluted DS, maintaining the DS concentration and producing clean water...
November 6, 2017: Scientific Reports
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"